Switching system for a moving unit guided along a track

ABSTRACT

The invention relates to a switching system for a moving unit especially an air-cushion vehicle guided along a track, to have a selective connection between a main track and either of two branch tracks. The switching system comprises an assembly of two track sections. This assembly is mounted on an axis of rotation which is external to each branch track. By operating this assembly around this axis of rotation, one of the desired connections between the main track and the branch tracks can be obtained through one of the track sections.

United States Patent r191 Mouillon Nov. 27, 1973 SWITCHING SYSTEM FOR AMOVING 3,670,659 6/1972 Schurch 104/96 NI GUIDED ALONG A TRACK 3,308,7663/ 1967 Urbinati 104/130 [75] Inventor: Paul Mouillon, Lyon, France 7Primary Examiner Gerald M Forlenza [73] Assignee: Maurice Barthalon,Verrieres-Lessistant ExarninerD. W. Keen B i (E fl France Attorney-1rvmS. Thompson et al.

[22] Filed: Mar; 10, 1972 ABSTRACT Appl. No.: 233,551

Foreign Application Priority Data Mar. 16, 1971 France 7109087 IReferences Cited UNITED STATES PATENTS 3/1970 Easton 104/23 FS 4/1967Lauber 104/101 The invention relates to a switching system for a movingunit especially an air-cushion vehicle guided along a track, to have aselective connection between a main track and either of two branchtracks. The switching system comprises an assembly of two tracksections. This assembly is mounted on an axis of rotation which isexternal to each branch track. By operating this assembly around thisaxis of rotation, one of the desired connections between the main trackand the branch tracks can be obtained through one of the track sections.

4 Claims, 10 Drawing Figures Pmmimm 1975 3, 774,544

SHEET 30F 6 Fig.3

SWITCHING SYSTEM FOR A MOVING UNIT GUIDED ALONG A TRACK This inventionrelates to a switching system for a moving unit which is guided along atrack, especially for a vehicle which is lifted by an air-cushion.

In known switching systems, use is made of a track section which isdisplaceable either in translational motion alone, or in a movement oftranslation associated with a movement of rotation about an axis atright angles to the plane of the tracks, or alternatively a rectilinealtrack section which is capable of rotational motion about an axis atright angles to the plane of the tracks. Apart from their substantialweight and high inertia, these systems involve time-consumingoperations.

Switching systems for suspended vehicles of the wheeled type are alsoknown which comprise a central switch constituted by a number ofelements pivotally coupled to each other and track sections whicharealso pivotally coupled so as to withdraw in certain positions of theswitch. These systems are complicated, exhibit high inertia and entail aconsiderable number of operations, which has a detrimental efiect ontheir reliability and on the conditions of safety.

In the case of vehicles which are lifted by an aircushion and suspendedfrom a track, it has been proposed either to construct a central switchcapable of moving in rotation about a center of rotation located in theswitch frog or to provide two retractable flanges in the lifting wall,one of the flanges being intended to complete the direct track whilstthe other completes the diverging track. This type of switch is,however, relatively complex andcostly.

Mention will finally be made of a track-changing device which isintended for a transporter having a track in the shape of an inverted T,in which a main track can be connected selectively to either of twobranch tracks disposed symmetrically with respect to the main track, byvirtue of a movable element which is pivotally coupled to the main trackand capable of rotating through an angle of 180 about an axis parallelto the axis of the main track. However, this device is limited to asymmetrical arrangement of the branch tracks.

The aim of the invention is to overcome the numerous disadvantages ofknown systems and to provide a switching system which is of simpleconstructional design, which is easy to operate and which can beemployed for any non-symmetrical turnout.

A further aim of the invention is to provide a switching system which isparticularly effective in the case of a vehicle which is lifted by anair-cushion.

In accordance with the invention, the switching sys-- tem for a movingunit guided along a track, especially for a vehicle lifted by anair-cushion, comprising an assembly of two track sections forselectively connecting a main track to either of two branch tracks, saidassembly being rotatably mounted about an axis, is characterized in thatthe axis of rotation is external to each branch track.

This arrangement has the advantage of facilitating the mid-point of theextremity of the main track to the mid-points of the correspondingextremities of the branch tracks.

This arrangement makes it possible to simplify the operation of thesystem to an even greater extent and has the further advantage ofenhancing the appearance of the structure.

In the event that the track extremities should not be located in thesame horizontal plane, the axis of rotation is located in the planebisecting the two planes which pass through said straight linesrespectively and which are perpendicular to the mid-plane of theterminal portion of the main track.

According to a further characteristic feature, the track sections arerelatively displaced through an angle which is substantially equal tothe angle of rotation and, in the case of rotation through the tracksections are disposed on each side of a plane which contains the axis ofrotation.

Preferably, the track sections are carried by a frame which is movableabout the axis of rotation and is coupled to a control unit placedbetween the branch tracks.

It is accordingly advantageous to ensure that the frame is rotatablymounted on the one hand with re spect to the main track and on the otherhand with respect to the branch tracks by means of two aligned shafts,the second shaft being coupled to the control unit.

Further properties of the invention will become apparent from thefollowing description, reference being made to the accompanying drawingswhich are given by way of non-limitative example, and in which FIG. 1 isa diagrammatic view in elevation, with portions broken away, showing aswitching system for connecting the tracks of a transporter of theair-cushion vehicle type FIG. 2 is a top view of the switching system inthe position of connection of the curved branch track FIG. 3 is asectional view taken along line IlI-Ill of FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 1, theswitching system being in the position of connection of the straightbranch track FIG. 5 is an end view of the switching system on the sidenearest to the main track FIG. 6 is a sectional detail view taken alongline VI-VI of FIG. 1

FIG. 7 is a partial longitudinal sectional view of the portions of thesystem which serve to rotate this latter switching system;

FIG. 9 is a diagrammatic end view of a switching system having an angleof rotation other than 180, this view being taken from the main trackFIG. 10 is an end view of the switching system of FIG. 9 in the sameposition but looking from the branch tracks.

There is shown diagrammatically in FIG. I a suspended-car transporter ofthe type described in French Pat. No 1 474 851 of Jan. 19th, 1966 in thename of the present Applicant as well as a switching system fortransferring the car or vehicle from the main track to either of the twobranch tracks.

The track is formed by a substantially continuous beam which isillustrated diagrammatically a more detailed description of this beammay be found in the above-mentioned patent.

The main track 1 is assumed to be rectilineal in the terminal portionwhich is adjacent to the switch. One of the branch tracks 2 is locatedin the line of extension of the main track whilst the other branch track3 has a certain degree of curvature. In this example, the branch tracksare located in the same horizontal plane and the track extremities to beconnected are located in the same vertical plane (see FIG. 2).

The tracks are supported by means of lateral pillars or posts forminggantries 4, two of which are provided at the ends of the tracks to beconnected on each side of the switch. The posts are relatively flexiblein order that expansion stresses should be reduced to a minimum.

The switching system 5 comprises two track sections, namely arectilineal section 6 corresponding to the branch track 2 and a curvedsection 7 corresponding to the branch track 3, said sections beingrigidly fixed to a steel latticework frame 8, said frame being capableof rotational motion about an axis XX which is external to each of thebranch tracks 2, 3.

The track sections 6,7 are rigidly fixed to the frame 8 by means oftie-rods 9 which permit positional adjustment of said track sectionswith respect to the tracks to be connected (see FIGS. 3 to 5).

In the example of construction under consideration, the two tracksections 6, 7 are disposed at an angle of 180 with respect to each otheron each side of a plane P which contains the axis of rotation XX (asshown in FIGS. 3 to 5) the angle of rotation is 180 and the axis ofrotation XX coincides with the line bisecting the angle made by thestraight lines D and D which joint the mid-point of the extremity of themain track 1 to the mid-points of the corresponding extremities of thebranch tracks 2, 3 (as shown in FIG. 2). Moreover, the mid-points of thebranch tracks 2, 3 are so designed as to be equidistant from themid-point of the main track 1 so that the axis XX is at right angles tothe plane of the extremities of the branch tracks.

The frame 8 is provided at each end with a crossmember 11, 12 (FIGS. 3to 5) which is adjacent to the main track or to the branch tracksrespectively and to which the track sections 6, 7 are attached in anadjustable manner by means of tie-rods l3.

Said cross-members 11, 12 respectively are rigidly fixed to two shortaligned shafts or stub-shafts 14, 15 which define the axis of rotationXX of the track sections and one of which, namely the stub-shaft 15, isactuated in such manner as to cause the frame 8 to rotate through anangle of 180 between the two positions of connection. Adjustable stops16 are provided on the beam 17 of each gantry 4 in order to arrest thecrossmembers in the appropriate position at the end of rotationalmotion. Locking of the system while in service can be ensured by meansof a locking-bolt (not shown).

The shafts 14, 15 are secured to the cross-members 11, 12 respectivelyand are each rotatably mounted in a spherical-bearing bushing 18, 19which is fixed on the beam 17 of the corresponding gantry 4, the bushing19 being disposed between the branch tracks.

The extremity of each track 1-3 is fitted with a retractable seal 21which can be applied against a complementary bearing provided on eachextremity of the corresponding track section 6, 7, at right angles tothe axis of rotation XX.

FIG. 6 illustrates a seal 21 of this type, as constituted by aninflatable envelope partially embedded in a sealholder 22 which isremovably secured to a flange 23 of the track. The envelope is connectedby means of pipes 24 to a suitable source of fluid under pressure aswill be explained in detail hereinafter. When in the inflated state,said envelope is applied against the complementary bearing surface 25formed by a plate 26 which is attached to a flange 27 of the tracksection such as the section 6. Perfect continuity of the beam whichserves as a track is thus ensured at the time of a connection. In theunconnected position, the clearance between a track section and thecorresponding track extremity is at least equal to 2 mm so as to makeallowance for free thermal expansion of these elements.

There are shown in FIG. 7 the stub-shafts 14, 15 which are hollow andeach fitted with a spherical bearing 31 mounted in the correspondingbushing 18, 19 which is attached to the beam 17 by means of a bearingsupport 32, 33. The bearing support 33 is secured by means of a flangedconnection to a hydraulic control motor 34 which is also carried by thebeam 17. The shaft 35 of the motor 34 and the stub-shaft 15 are coupledtogether by means of a splined torsion shaft 36 which permits bendingmovements resulting from faulty alignment of the axis of rotation withrespect to the axis of the drive shaft. This lack of coincidence mayresult from faulty construction or adjustment or from deformationsarising from static, dynamic and thermal stresses in the movable frameand the gantries.

In the case of a moving unit which is displaced by electric power, it isevidently possible to associate with each track section a conductiveelement which ensures continuity of the electric power supply.Interruption of the supply can serve as a safety signal for preventingaccess to one of the tracks by the moving unit, which can thus no longerbe guided.

In the case in which the moving unit is displaced by means of a linearelectric motor, the secondary winding being connected to the track, thetrack sections are each fitted with a secondary-winding element withoutmaking it necessary to take any special precaution since the alignmentof the motor is ensured by reason of the continuity of the tracks.

The hydraulic motor 34 can be replaced by a control unit comprising twohydraulic jacks, the operating rods of which are aligned and coupledtogether in such manner as to actuate a rotating mechanism which iscoupled to the drive shaft 35.

This device, which will be described with reference to FIG. 8, serves totransfer the switching system from one position of connection to theother while ensuring positional control and operational safety.

The hydraulic control unit comprises a low-pressure hydraulic pump 41which is supplied from a hydraulicfluid reservoir 42 and connected to anoleopneumatic accumulator 43 this latter supplies a three-wayelectro-valve 44 which is connected to the reservoir 42 by means of adischarge pipe 45. The electro-valve 44 has two solenoids 46, 47 whichcan be excited separately so that, in a neutral position correspondingto nonexcitation of the two solenoids, the hydraulic lowpressure istransmitted to two outlet pipes 48, 49 when the solenoid 46 is excitedand the solenoid 47 is not excited, the pipe 48 is supplied whilst thepipe 49 is discharged, and conversely, when the solenoid 47 is excitedand the solenoid 46 is not excited.

The pipes 48, 49 terminate respectively in two control push-rod elements51, 52 which operate a threeposition valve 53, said valve being suppliedby a highpressure hydraulic pump 54 which is connected to a reservoir55. The valve 53 is connected to the reservoir 55 by means of adischarge pipe 56 and operates in the same manner as the electro-valve44 under the control of the push-rod elements 51, 52 in order that thehydraulic-high-pressure may be transmitted either simultaneously orselectively to two outlet pipes 57, 58.

The pipes 57, 58 are each connected to a simple spring-loadedslide-valve 61, 62 which serves to put said pipes into communicationwith pipes 63, 64 respectively. Moreover, the pipes 57, 58 are eachconnected to a two-way slide-valve 65, 66' respectively, saidslide-valve being associated with a locking device as will be explainedhereinafter.

Each slide-valve 61, 62 is controlled by a hydraulic push-rod element67, 68 and this latter is supplied by means of a pipe 71, 72 which canbe put into communication with the pipe 48, 49 by means of the two-wayvalve 65, 66 when said valve is in the locking position.

The seals 21 which are associated with the branch tracks are supplied inparallel with the hydraulic pushrod elements 67, 68 whilst the seal 21which is associated with the main track is supplied through either ofthe two pipes 71, 72 by means of a free slide-valve 73 which makes itpossible to isolate one of the seals 21 and to supply the seal 21 in allcases.

The pipes 63, 64 which come from the valves 61, 62 are connectedrespectively to position detectors constituted by slide-valves 74, 75which serve to detect the position of the switch at the end of travel.These slidevalves are capable of putting the pipes 63, intocommunication with high-pressure pipes 76, 77 respectively whichterminate in cylinders 78, 79 of the springloaded piston type whichconstitute locking devices, the rods of which control the slide-valves65, 66. The slide-valves 74, 75 make it possible in another position toestablish a communication between the pipes 76, 77 by virtue of anintermediate pipe 80.

The two hydraulic actuating jacks 81, 82am connected to the slide-valves65, 66 respectively by means of pipes 83, 84 which communicate with thepipes 57, 58 when these valves are in the unlocking position. Two pipes85, 86 serve to establish a circulation of fluid from the jacks 81, 82to the pipes 77, 76 respectively, and only in this direction, by meansof non-retum valves 87, 88.

The operation of this hydraulic control unit will be explained in thecase of changeover of the switching system from the position ofconnection of the curved branch track 3 to the position of connection ofthe straight branch track 2.

Initially, the branch track 3 being connected to the main track 1, thejack 82 is located at the end of travel with its operating rod in theoutwardly extended positions, and the jack 81 is located at the end oftravel with its rod in the inwardly withdrawn position. The seal 21 ofthe branch track 3 and the seal 21 of the main track 1 are in theinflated state the position detector 74 is actuated by the switchingsystem and the slide-valve 65 is in the locked position by virtue of theaction of the restoring spring of the locking cylinder 78.

The self-excitation circuit of the solenoid 36 of the electro-valve 44is energized, with the result that the pipe 48 is put into communicationwith the discharge pipe 45. In consequence, the pressure drops withinthe pipe 71, the seal 21 associated with the branch track 3, the seal21' associated with the main track 1 and the hydraulic push-rod element67. The valve 61 is then returned by its spring to the position in whicha connec tion is established between the pipes 57 and 63.

The control push-rod element 52 associated with the valve 53 is putunder pressure by reason of the fact that t the pipe 49 is suppliedwhilst the control push-rod element 51 is discharged. The valve 53 thensupplies the pipe 57 and the pipe 58 is discharged. In consequence, thejack 82 is relieved by means of the pipes and 58 and by means of theslide-valve 66 which is in the unlocking position. At the same time, thepipes 57, 63 and 76 are put under pressure and the slide-valve 65 isunlocked under the action of the rod of the cylinder 78. The valve 65establishes a connection between the pipes 83 and 57, with the resultthat the jack 81 is supplied. The switching system is therefore moved tothe position of connection of the branch track 2.

The position detector 74 then puts the pipes 76 and 77 intocommunication by means of the intermediate pipe 80, thereby ensuringpositional maintenance of the locking devices 78 and 79. At the end oftravel, the detector puts the pipes 64 and 77 into communication, withthe result that the locking device 79 is discharged. The jack 81, whichis connected through the pipe 86 to the pipe 77, is also relieved. Theslide-valve 66 is actuated when the rod of the cylinder 79 is returnedby its spring so as to establish a connection between the pipes 49 and72. The seal 21 associated with the branch track 2 and the seal 21'associated with the main track 1 are inflated and the hydraulic push-rodelement is supplied.

An end-of-travel contact (not shown) interrupts the excitation of thesolenoid 46, thus permitting the return of the electro-valve 44 and thevalve 53 to the neutral position. The switching system takes up theposition of connection of the branch track 2. It will be noted that theangle of rotation can be of any desired value although an angle of 180has been given by way of example in the figures referred-to above.

W6. 9 shows diagrammatically the moving portion of a switch designed fora rotation through an angle a other than 180, the axis of rotation X-Xbeing located at the end and it is' noted in comparison with the switchdesigned for rotation through 180 that the axis of rotation is locatedat a distance from the track sections 90 and 91.

FIG. 16 shows diagrammatically the moving portion of the same switchwith the extremities 92 and 93 of the traclc sections 90 and 91 at theend nearest to the branch tracks.

The branch track 94 would be in register with the extremity 92 afterrotationof the track sections through an angle a in the direction of thearrow. By means of a chain-dotted line which has a slightly embracingform for the sake of enhanced clarity, there can also be seen the branchtrack 95 which is in register with the extremity 93 of the connectedtrack section.

It is apparent from FIG. 10 that one of the branch tracks is at adifferent height with respect to the other track at the level ofconnection of the moving portion of the switch and that one of the tracksections (or both sections) has a variable angle of tilt along theswitch.

The switching system which has just been described has many advantagesby reason of its simplicity of construction, its small overall size, thespeed with which it can be operated and its outstanding reliability.Moreover, in the case of air-cushion vehicles, the inflatable sealsensure a very high standard of leak-tightness in the retracted state,any contact is eliminated, thereby reducing friction solely to that ofthe bearings and permitting substantial variations in play arising frommanufacturing tolerances and from the action of thermal expansionstresses.

The spherical bearings ensure accurate maintenance of the distanceimposed by the movable sections and serve to lighten or even to dispensewith thrust bearings. However, a design solution involving the use ofconventional joumal-bearings and thrust-bearings remains applicable andcan constitute an alternative form of construction.

Furthermore, the control unit 34 can also consist of an electricreduction gear motor.

What I claim is:

l. A switching system for a moving unit guided along a track, especiallyfor a vehicle supported by an air cushion, comprising an assembly of twotrack sections for selectively connecting a main track to either of twobranch tracks, said assembly being rotatably mounted about an axis ofrotation which is external to each branch track, wherein each track ortrack section extremity is fitted with a retractable seal which iscapable of cooperating with a bearing surface formed on thecorresponding track or track section extremity.

2. A system according to claim 1, wherein, in the case of an air-cushiontransporter, the seal is constituted by an inflatable envelope whichensures leak-tightness between the track section and the connectedtrack.

3. A system according to claim 1, wherein the seals associated with thebranch tracks are disposed in the same plane at right angles to the axisof rotation.

4. A switching system for a moving unit guided along a track, especiallyfor a vehicle supported by an air cushion, comprising an assembly of twotrack sections for selectively connecting a main track to either of twobranch tracks, said track sections being carried by a frame which ismovable about an axis of rotation external to each branch track and iscoupled to a control unit placed between the branch tracks, said controlunit comprising two jacks associated with means for converting a linearmovement into a rotational movement.

1. A switching system for a moving unit guided along a track, especiallyfor a vehicle supported by an air cushion, comprising an assembly of twotrack sections for selectively connecting a main track to either of twobranch tracks, said assembly being rotatably mounted about an axis ofrotation which is external to each branch track, wherein each track ortrack section extremity is fitted with a retractable seal which iscapable of cooperating with a bearing surface formed on thecorresponding track or track section extremity.
 2. A system according toclaim 1, wherein, in the case of an air-cushion transporter, the seal isconstituted by an inflatable envelope which ensures leak-tightnessbetween the track section and the connected track.
 3. A system accordingto claim 1, wherein the seals associated with the branch tracks aredisposed in the same plane at right angles to the axis of rotation.
 4. Aswitching system for a moving unit guided along a track, especially fora vehicle supported by an air cushion, comprising an assembly of twotrack sections for selectively connecting a main track to either of twobranch tracks, said track sections being carried by a frame which ismovable about an axis of rotation external to each branch track and iscoupled to a control unit placed between the brancH tracks, said controlunit comprising two jacks associated with means for converting a linearmovement into a rotational movement.